1. Field of the Invention
The present invention relates to a navigation system which displays the current location of a mobile object on a map and guides the travel route of the mobile object, and more particularly, to an apparatus and method for processing traffic information, wherein a navigation system receives and processes real-time traffic information that is collected through various channels and is broadcast as an FM multiplex broadcast by a traffic information center.
2. Description of the Related Art
With the continuous increase of various kinds of mobile objects including vehicles, traffic congestion has become serious. Specifically, there is a serious problem in that the increase of mobile objects has overtaken the rate of expansion of roads. A navigation system draws attention as one solution to traffic congestion. A navigation system receives navigation messages transmitted by GPS (Global Positioning System) satellites, detects the current location of a mobile object, matches the current location of the mobile object to map data, and displays the current location of the mobile object together with a map on a display unit.
Therefore, a user of a mobile object can check the current location of the mobile object and the shortest route from the current location to a destination. In addition, the user can efficiently utilize a given road network by scheduling a travel route from the current location of the mobile object to the destination according to guidance from the navigation system, and by causing the mobile object to travel along the scheduled travel route.
Meanwhile, a traffic information center collects traffic information on respective roads in real-time through various channels, and broadcasts the collected real-time traffic information via an FM multiplex broadcast.
Therefore, a manufacturer of a navigation system provides a user of a mobile object with traffic information on roads around the current location of the mobile object, through the navigation system which receives real-time traffic information broadcast by a traffic information center via the FM multiplex broadcast, displays on a display panel the received traffic information together with a map of roads where the mobile object will travel. In addition, when searching for a travel route from the current location of a mobile object to a destination, a navigation system searches for an optimal route along which the mobile object can travel to the destination in the shortest period of time, with reference to the received traffic information.
When the navigation system receives and processes the traffic information via the FM multiplex broadcast, according to a conventional scheme, all the traffic information sorted by a traffic information sorting unit is stored in a traffic information storage unit and then displayed on a display unit after the stored traffic information is matched to map data by a matching unit.
Therefore, the storage capacity of the traffic information storage unit in which traffic information is stored has to be so large as to store the traffic information broadcast by the traffic information center. In addition, the matching unit compares every road displayed on a map with the traffic information stored in the traffic information storage unit, retrieves the traffic information relevant to each road, matches the retrieved traffic information to the map, and displays the information on a display unit. Therefore, the matching unit has a large amount of calculation and needs a great deal of time, so that traffic information is very difficult to display in real-time.
In addition, in order to match the traffic information broadcast by the traffic information center to each road on a map and display the information thereon, a coordinate system for map data used by the traffic information center for broadcasting the traffic information has to be identical with that for map data used by a navigation system. However, the traffic information center broadcasts the traffic information using DARC (Data Radio Channel) map data, while the navigation system uses different map data provided by each manufacturer thereof, causing problems in that the traffic information broadcast by the traffic information center cannot be matched directly to the map data used by the navigation system.
Therefore, in the navigation system, the map data for use in broadcasting the traffic information by the traffic information center have to be matched to the map data used by the navigation system, and, using the matching information of the map data, the traffic information has to be matched to the map data used by the navigation system.
In addition, when a conventional navigation system retrieves the travel speed of a mobile object on each road from the received traffic information, matches it to map data, and displays it on a display unit, the color of a road is displayed in accordance with the travel speed of the mobile object but the direction of the displayed travel speed is not displayed. Therefore, there is a problem in that a user of the navigation system cannot identify which travel direction a travel speed on a relevant road corresponds to, based on the displayed color of the road. That is, since roads generally allow two-way traffic, there is a problem in that it is impossible to determine whether the travel speed displayed with a predetermined color is in a forward direction or in an opposite direction on the corresponding road.